This is one of the roots of your error, bigcalv. I testify to you that the love in gay marital relationships IS AGAPE and not merely eros, though the latter does seed and reinforce the former (just because humans can make separate Greek words doesn't mean that the referents in reality are utterly separate). However, when it comes to one lover looking after another in the late stages of an ugly, fatal disease, or two old guys with erectile dysfunction carrying on their couplehood as always, it becomes pretty darned obvious that the motor of these relationships is God's own agape.

Go meet several gay Christian couples (not just one; you may by chance meet bad examples) and let the spirit testify in your heart as to what you see.

I pray you will dwell in God's world as much as in God's book. Yes, I know the former is fallen. Just take that into account in a matter-of-fact way, without undue abhorrence - you do have the Spirit as your counsellor as you go observing. Yes, observing.